Iteration based method and/or apparatus for offline high quality encoding of multimedia content

Abstract

A method for encoding video, comprising the steps of (A) encoding a number of frames of a video signal using a first sub-set of encoding parameters, (B) analyzing the encoded frames to find and mark reference frames that are used more than a predetermined number of times, and (C) re-encoding the video signal using a second sub-set of encoding parameters different than the first sub-set of encoding parameters when re-encoding the marked reference frames.

What is claimed is: 
     
       1. A method for encoding video, comprising the steps of:
 (A) Encoding a number of frames of a video signal using a first sub-set of encoding parameters; 
 (B) Analyzing said encoded frames to find and mark reference frames that are used more than a predetermined number of times; and 
 (C) Re-encoding said video signal using a second sub-set of encoding parameters different than said first sun-set of encoding parameters when re-encoding said marked reference frames. 
 
     
     
       2. The method according to  claim 1 , further comprises:
 repeating steps (A)-(C) until a predetermined criteria is met. 
 
     
     
       3. The method according to  claim 1 , wherein said first sub-set of encoding parameters and said second sub-set of encoding parameters are adjusted for each frame. 
     
     
       4. The method according to  claim 1 , wherein said first sub-set of encoding parameters includes quantization parameters. 
     
     
       5. The method according to  claim 1 , wherein said second sub-set of encoding parameters includes selecting an encoding mode. 
     
     
       6. The method according to  claim 5 , wherein said encoding mode is selected from the group consisting of Inter, Intra bi-directional prediction, direct prediction and Skip. 
     
     
       7. The method according to  claim 1 , further comprising the step of:
 archiving said re-encoded video signal. 
 
     
     
       8. The method according to  claim 1 , wherein steps (A)-(C) are performed on a scene of a video signal. 
     
     
       9. The method according to  claim 5 , wherein steps (A)-(C) are repeated for a subsequent scene of said video signal. 
     
     
       10. The method according to  claim 1 , wherein steps (A)-(C) are performed on a group of pictures of a video signal. 
     
     
       11. The method according to  claim 5 , wherein steps (A)-(C) are repeated for a subsequent group of pictures of said video signal. 
     
     
       12. The method according to  claim 1 , wherein step (A) comprises the sub-steps of:
 (i) Performing motion estimation for each frame in the input sequence and each encoding mode; 
 (ii) Evaluating the quality of the encoded frames when each mode is selected; and 
 (iii) Selecting the mode that leads to the best coded representation for the frame, and repeating (i)-(iii) until all the frames in the input sequence has been processed. 
 
     
     
       13. The method according to  claim 1 , wherein step (B) comprises the sub-steps of:
 (i) evaluating every frame in the sequence for the number of times each reconstructed pixel in a coded frames has been referenced; and 
 (ii) adjusting the encoding parameter for each encoding partition in the current frame so that the reconstruction of the current frame when encoded with the first sub-set of parameters is as close to the values determined in step (i). 
 
     
     
       14. The method according to  claim 1 , wherein said method is implemented in an MPEG/H.26x video encoder. 
     
     
       15. An apparatus for encoding video comprising:
 means for encoding a number of frames of a video signal using a first sub-set of encoding parameters. 
 means for re-encoding said video signal using a second sub-set of encoding parameters different than said first sub-set of encoding parameters when re-encoding said marked reference frames. 
 
     
     
       16. An apparatus comprising:
 a first circuit configured to encode frames of a video signal using a first sub-set of encoding parameters; 
 a second circuit configured to buffer said encoded frames; 
 a third circuit configured to analyze said encoded frames to find and mark reference frames that are used more than a predetermined number of times; and 
 a fourth circuit configured to re-encode said video signal using a second sub-set of encoding parameters different than said first set of encoding parameters. 
 
     
     
       17. The apparatus according to  claim 16 , wherein (i) said first circuit repeats said encoding based on an updated first sub-set of encoding parameters adjusted based on said fourth circuit re-encoding said video signal and (ii) said first circuit and said fourth circuit are configured to alternate encoding and re-encoding until a predetermined criteria is met. 
     
     
       18. The apparatus according to  claim 16 , further comprising archiving said re-encoded video signal. 
     
     
       19. The apparatus according to  claim 16 , wherein said apparatus comprises a video encoder system. 
     
     
       20. A non-transitory computer readable medium configured to execute the steps of  claim 1 .